Telephone-transmitter



P. vL. JENSEN. TELEPHONE TRANSMITTEL vAPPLicAUoN FILED Mn. 2. 191s.

Patented Mar.' 2, 1920;

S woe 144501 l insecte.

PETER JENSEN, 0F SAN FRANCISCO, CALIFRNIA, ASSIGNGE T@ THE MAGNAVQX CGMNY, 0F SAN FRANCISCO, CALIFDRNIA, A CORPORATIN OFALIFRNIQ TELE?HNE-TRANSISIEITTB.

. citizen of the Unit-ed States, residing at San Francisco, in the county of San Francisco and Stateof California, have invented cer- 'tain new and useful Improvements in rlelephone-Transmitters; and I do hereby declare the following to be a full, clear, and exact description o' the same, reference being had to the accompanying drawings, forming part of this specification, and to the gures land letters of reference marked thereon.

In a previous application filed by myself and Pridham,Serial No. 187,361, there is illustrated and described a telephone transmitter designed and adapted for use in situations where it i-s subjected to extraneous sound waves as contradistinguished from vocal mund waves, one particular field of useulness'bein in connection with aeroplane work in or er to facilitate communication between the occupants of the plane. In designing the transmitter of said 4previous application, the construction adopted was one in which the diaphragm is exposed substantially equally on both sides to all extraneous sound waves, but so located with respect to the mouth of the user that vocal sounds to be transmitted impinge upon the diaphragm on one side only and that side is usually the side opposite to the electrode cell which functions to vary the current, in accordance with well known practice. said prior application, the transmitter is adapted to be held close to the face of the user with the diaphragm spaced' al suitable distance in front of the users mouth by an Specication of Letters Patent.

Application led January 2, 191e.

In the device of,

ject of the present invention to provide an improved construction and arranoement whereby the transmitter will be positioned and held with relation to the face and mouth of the user by face-engaging pads rest-ing against the users face at each side of the mouth only, thus leaving a completely free and unobstructed space at the top and bottom of the diaphragm and between said diaphragm and the users face. In carrying the invention into practice, it is preferred to provide face-engaging pads which may be deformed to conform to the lines of contour or comfort for the particular user and the whole device is held in place by straps or .Patented Mar. 2, delgi).

serial. no. einem;

users head or by other suitable fastening y .means attached to the pads themselves at points which will substantially insure the suspension oit' the diaphragm in proper rela-v tion tothe mouth of the user to secure the most effective action9 regardless of whether or not the users head is in an upright or in an inclined position.

Referring to the accompanying draw- 1ngs,- p

Figure 1 is an elevation showing a transmitter embodying the present improvements held in place by a strap or band passing around the head.

Fig. 2 is a top plan view of the transmitter showing the face-engaging pad supporting plates without a covering thereon.

Fig-3 is a side elevation of the structure shown in Fig. 2.

F ig. 4.- is a perspective view of one of the pad-supporting plates, which under certain circumstances might serve as the pad itself.

The parts of the structure shown, which may be called the trame of the transmitter embody an annular or ring-like support A in which the diaphragm B is mounted in any ordinary or preferred manner, and a cross bar C spaced from and rigidly connected with the ring A by posts I). cell E is located between the bar C and diaphragm and the circuit terminal connections F extend to suitable 'binding posts f on the. bar from whence the circuit connections lead to the electrode cell in the usual way. In accordance with the present invention the annular or ring-like frame A is provided withl projections or standards G conveniently integral therewith and preferably iat or having flat faces for the reception of suitable guiding and clamping means adapted to cooperate with corresponding posts or lugs H Aformed on the pad plates'I. A convenient.

and rigid form of connection consists-in rIhe electrode forming the lugs or posts H with slots k in v such size and so spaced as to aord a com.

ortable bearing against the sides of the ace of the user, and at the same time when I pressed against the face, to properly' hold the diaphragm in place for use. 4

Inasmuch as it 1s a desideratum to avoid the transmission of sound waves to the diaphragm through any of the metal parts of the apparatus or to avoid setting up al resonant vibration due to non-vocal sound Waves, it is preferred that the metal parts of the device should be made of a non-resonant metal, and for this reason as well as forthe comfort of the user, the pad plates I are preferably covered with nonheat-conducting, non-resonant material, such as animal fur, indicated' at K in Fig. 1. Obviously, however, any nonheat-conducting material may be utilized for this urpose, especially an substance which Will not tend to slip or sllde when in contact With the skin. The whole device is adapted tobe held in place by supportin means cooperating with studs z' located on t e pad plates, preferably' at points intermediate the centers and upper ends, and for coperation with these studs there may be suitable connections with the helmet of the user, or an adjustable supporting strap, such-` as M, extending around the head may be provided.

Ihe provision of separate and distinct face-engaging pads located at each side of the transmitter is highly advantageous for a number of reasons, but mainly because it leaves a free unobstructed opening up and down in front of the mout-h of the user, with the result that the breath may escape freely, resulting in less difliculty from condensation flying at great altitudes and in extreme cold.

Furthermore, it gives the user an opportunity to reach his mouth and nasal organs, should this be desirable -orv necessary, land it is especially important in that it permits, extraneous sound waves to reach boththe inner and outer. sides of the diaphragm with practically equal facility and consequently such sound Waves, acting on diametrically opposite sides of the diaphragm simultaneously, produce little or no effect which will interfere with the transmission of vocal sounds.

In order to permit'the pads to be fashioned to fit the face of the particular user the pad plates ,are preferably formed of metal which may be bent and twisted into the desired shape, as, vfor example, relatively soft brass, care being ltaken, however, that the metal shall be sufficiently strong and rigid to hold the transmitter against displacement by strains to which it may be subjected in use.

What is claimed is:

1. In a telephone transmitter, in j which the-diaphragm is exposed on opposite sides to non-vocal sound waves, of supporting means for positioning the transmitter with its diaphragm in position to receive the direct impact of vocal soundwaves on one side only, embodying independent face-engaging pads spaced -from the edges of the diaphragm and from each other, and means for holding said pads in position against the face of the userwith the diaphragm in front of the mouth. v

2. In a telephone transmitter of the char-v acter specied in claim 1, face engaging pads embodying deformable metal plates adapted to be bent to conform to the face of the user.

3. In a telephone transmitter of the character specified in claim l, face engaging pads embodying non-resonant covering material adapted to rest against the faceof the user.

4.-. In a telephone transmitter of the character specified in claim 1, laterally spaced face engagin pads, and posts connecting said pads an transmitter, whereby a clear space is provided above and below the mouth of the user. j

' 5. In. a telephone transmitter, a frame, a transmitter diaphragm supported in said frame and exposed on opposite sides equally to non-vocal sounds, -adjustable posts carried by the frame, face-engaging'pads carried by the posts in laterally spaced relation and supporting strap connections with the pads 4for retaining the pads in contact with the face of the user and the diaphragm in front of the users mouth in position to receive vocal sounds directly on one side.

6. In a telephone transmitter, a circular frame having posts projecting therefrom on one side, a diaphragm mounted in the frame and freely exposed on both sides to sound vibrations,`separate face engaging pads adjustably mounted one on each post for location a greater or less dista-noe from the plane of the diaphragm, means for' fastening said pads in adjusted position, and means for holdino` the pads .aga-inst the face of the user with the'diaphragm in position to receive vocal soundson one sideA only and with an unobstructed space at the top and bottom of the diaphragm.

PETER L. JENSEN. 

